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THEY WILL HAVE HIGHER RUNOFF CHARACTERIATICS. SOME DRAINAGE <br />AREAS C0r1TAIN AREAS THAT HAVE BEEN UNAFFECTED OR <br />REVEGITATED. THF. COEFFICIENTS FOR THESE AREAS REFLECT THE <br />COMBINATION OF FIIGH AND LOW RUr10FF CHARACTERISTICS. THE <br />REFUSE PILES. THOUGH NOT PRESENTLY VEGITATED, ARE RELATIVELY <br />PERMIABLE AND 41ILL YIELD LITTLE RUNOFF. THE RUNOFF <br />COEFFICIENTS FOR THESE AREAS HAVE. HOWEVER, BEEN ESTIMATED <br />FOR THEIR FINAL REVEGITATED STATE WHICH WILL HAVE A GREATER <br />RUNOFF POTENTIAL. <br />THE RATIONAL METHOD OF STORM RUNFF CALCULATION WAS USED <br />THROUGHOUT. AS RUNOFF FROM DIFFERENT AREAS REPORTS TO A <br />GIVEN CHANr1EL. THE TOTAL OF THE PEAK RUNOFF FLOWS WAS USED <br />AS THE DESIGN FLOW FOR THE CHANNEL. RATHER THAri <br />RECALCULATING A NEW. LONGER. SATURATION PERIOD AND LESSER <br />FLOW. THIS CALCULATION YIELDS A SIMPLER AND MORE <br />CONSERVATIVE DESIGN. ALL FORMULAS AND COEFFICIENTS FOR <br />CALCULATING SURFACE RUNOFF CAME FROM )~AAN AND BARFIELD. <br />OPEN CHANr1EL FLOWS WERE CALCULATED WITH MANNINGS EQUATION. <br />ALL CULVERTS WERE DESIDNED TO RUN OPEN SO NO ADDITIONAL <br />STRUCTURES WOULD BE NECESSARY TO PROVIDE HEAD TO THE PIPES. <br />CMP-4 DOES HOWEVER r.url FULL: THE HEAD IS PROVIDED BY THE <br />DROP IN THE PIPE ArID ONLY EPIOUGH WATER TO INUNDATE THE <br />ENTRANCE I5 REQUIRED. Irl CALCULATING PEAK RUNOFFS FOR Tl1E <br />INDIVIDUAL AREAS THE RAINFALL INTENSITY FOR A STORM DURATION <br />EQUAL TO THE TIME OF CONCFIITRATION FOR THAT AREA AND HAVING <br />A STORM OCCURArICE FREOIIENCY OF TEN (10) YEARS WAS USED. <br />9 <br />